The overall objectives of this project are to attempt to identify the individual differences in the behavioral repertoire of infants and to determine how these differences interact with environmental experiences to result in particular developmental outcomes in normal and risk populations. In pursuit of thes goals we have developed an observational system to make a comprehensive record of mother-infant-environment interactions which we use in combination with infant assessment to look for interactive functions. The proposed program of work for the coming year includes continuation of NBAS-K data collecting on a normal sample of newborn infants, follow-up of original study infants at eight and ten months of age, observation of an intensive care unit for newborns and evaluation of risk infants using a modified version of the neonatal behavioral assessment scale. Data analysis will be aimed at identifying individual infant characteristics as they interact with caregiver and environmental stimulation.